Lowered plasma paraoxonase (PON)1 activity is a trait marker of major depression and PON1 Q192R gene polymorphism-smoking interactions differentially predict the odds of major depression and bipolar disorder

Study on exosomes for identifying bipolar disorder in early stage: A cross-sectional and validation study protocol

BACKGROUND

The difficulty is remained to accurately distinguish bipolar disorder (BD) from major depressive disorder (MDD) in early stage, with a delayed diagnosis for 5-10 years. BD patients are often treated with antidepressants systematically due to being diagnosed with MDD, affecting the disease course and clinical outcomes. The current study aims to explore the role of plasma exosomes as biomarker to distinguish BD from MDD in early stage.

METHODS

Two stages are included. The first stage is a cross-sectional study, comparing the concentrations of plasma exosome microRNA and related proteins among BD group, MDD group, and healthy controls (HC) group (n = 40 respectively), to identify target biomarkers preliminarily. The "Latent Class Analysis" and "Receiver Operating Characteristic" analysis will be performed to determine the optimal concentration range for each biomarker. The second stage is to validate target markers in subjects, coming from an ongoing study focusing on patients with a first depressive episode. All target biomarkers will be test in plasma samples reserved at the initial stage to detect whether the diagnosis indicated by biomarker level is consistent with the diagnosis by DSM-5. Furthermore, the correlation between specific biomarkers and the manic episode, suicidal ideation, and adverse reactions will also be observed.

DISCUSSION

Exosome-derived microRNA and related proteins have potential in serving as a good medium for exploring mental disorders because it can pass through the blood-brain barrier bidirectionally and convey a large amount of information stably. Improving the early diagnosis of BD would help implement appropriate intervention strategy as early as possible and significantly reduce the burden of disease.

Reverse cholesterol transport and lipid peroxidation biomarkers in major depression and bipolar disorder: A systematic review and meta-analysis

BACKGROUND

Major depression (MDD) and bipolar disorder (BD) are linked to immune activation, increased oxidative stress, and lower antioxidant defenses.

OBJECTIVES

To systematically review and meta-analyze all data concerning biomarkers of reverse cholesterol transport (RCT), lipid-associated antioxidants, lipid peroxidation products, and autoimmune responses to oxidatively modified lipid epitopes in MDD and BD.

METHODS

Databases including PubMed, Google scholar and SciFinder were searched to identify eligible studies from inception to January 10th, 2023. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed.

RESULTS

The current meta-analysis included 176 studies (60 BD and 116 MDD) and examined 34,051 participants, namely 17,094 with affective disorders and 16,957 healthy controls. Patients with MDD and BD showed a) significantly decreased RCT (mainly lowered high-density lipoprotein cholesterol and paraoxonase 1); b) lowered lipid soluble vitamins (including vitamin A, D, and coenzyme Q10); c) increased lipid peroxidation and aldehyde formation, mainly increased malondialdehyde (MDA), 4-hydroxynonenal, peroxides, and 8-isoprostanes; and d) Immunoglobulin (Ig)G responses to oxidized low-density lipoprotein and IgM responses to MDA. The ratio of all lipid peroxidation biomarkers/all lipid-associated antioxidant defenses was significantly increased in MDD (standardized mean difference or SMD = 0.433; 95% confidence intervals (CI): 0.312; 0.554) and BD (SMD = 0.653; CI: 0.501-0.806). This ratio was significantly greater in BD than MDD (p = 0.027).

CONCLUSION

In MDD/BD, lowered RCT, a key antioxidant and anti-inflammatory pathway, may drive increased lipid peroxidation, aldehyde formation, and autoimmune responses to oxidative specific epitopes, which all together cause increased immune-inflammatory responses and neuro-affective toxicity.

Tissue-Specific Oxysterols as Predictors of Antidepressant (Escitalopram) Treatment Response in Patients With Major Depressive Disorder

Background

There is growing evidence that disturbances in cholesterol metabolism may be involved in major depressive disorder (MDD). However, it is not known if cholesterol metabolites present in the brain and periphery can be used to diagnose and predict an MDD patient's response to antidepressant treatment.

Methods

A total of 176 subjects (85 patients with MDD and 91 healthy control subjects) were included in this study. The expression of peripheral and brain-specific oxysterols and related gene polymorphisms were investigated in all subjects. The severity of depression was measured using the 17-item Hamilton Depression Rating Scale, 16-item Quick Inventory of Depressive Symptoms-Self-Report, and Patient Health Questionnaire-9 for all patients with MDD before and after 12 weeks of antidepressant treatment.

Results

Patients with MDD expressed higher plasma levels of 24(S)-hydroxycholesterol (24OHC) (mainly secreted from the brain) compared with healthy control subjects, and the higher levels of 24OHC were associated with 24OHC synthetase (CYP46A1) gene polymorphisms. In patients with MDD, an improved response to the 12-week antidepressant treatment was associated with a reduction of both 24OHC and 27OHC (mainly secreted from the peripheral system) levels relative to baseline levels. Nonresponders exhibited increased levels of oxysterols at the end of treatment compared with baseline. The superior reduction in oxysterol levels correlated with better outcomes from the antidepressant treatment.

Conclusions

These data suggest a potential role for oxysterols as diagnostic and treatment response-related indicators for MDD.

Neurobiological associations between smoking and internalizing disorders

People with severe mental disorders have a higher mortality rate due to preventable conditions like cardiovascular diseases and respiratory diseases. Nicotine addiction is a preventable risk factor, with tobacco use being twice as high in people with mental disorders. An integrative model that divides mental disorders into externalising, internalising, and thought disorders could be useful for identifying common causalities and risk factors. This review aims to examine the interface between smoking and internalising disorders, specifically schizophrenia, depressive disorders, and anxiety disorders. The review finds that there is a clear association between smoking behaviour and these disorders. Schizophrenia is associated with polymorphisms that result in an imbalance between glutamate and GABA release and abnormalities of dopaminergic pathways. Nicotine improves dopaminergic signalling and balances glutamatergic and GABAergic pathways, improving symptoms and increasing the risk of nicotine dependence. In depressive disorders, smoking is associated with functional changes in brain regions affected by smoking and self-medication. In anxiety disorders, there is a bidirectional relationship with smoking, involving the amygdala and changes in dopaminergic pathways and cortisol production. Smoking poses a threat to people living with psychiatric disorders and calls for further research to assess the interactions between nicotine dependence and internalising and thought disorders.

Cigarette smoking and risk of suicide in bipolar disorder: a systematic review

Objective

Bipolar disorder (BD) is a highly prevalent, chronic and recurrent mental illness. The smoking rates in patients with BD are much higher than those of the general population, and BD is associated with an increased risk of suicide. An association between smoking and suicidal behavior has been found in the general population, this systematic review examines whether there is evidence of an association between smoking and suicide behavior in patients with BD.

Method

A database search was carried out in Medline, Embase, The Cochrane Library, Scopus, and Web of Science, updated until December 31st, 2021, according to the 2020 PRISMA guidelines. We identified prospective and retrospective studies that included patients diagnosed with BD types I, II, and not otherwise specified, and in which smoking and suicidal behavior were correlated. Articles that focused exclusively on other mental disorders were excluded. The Ottawa-Newcastle scale was used to assess the methodological quality of the included articles.

Results

Fifteen articles (n = 7,395) met all the inclusion criteria. In nine of these articles, the authors found an association between smoking and suicidal behavior in BD, while in the remaining six articles, this association was not found. A great deal of variability was observed between articles, particularly in the measurement of suicidal behavior and tobacco consumption. The risk of bias, as assessed by the NOS, was high for most of the included articles, except for two papers, whose risk was low.

Conclusion

It was not possible to establish a clear relationship between tobacco use and the risk of suicide in BD patients due to the heterogeneity of the articles included in this systematic review, which had different sample sizes and methodological issues. However, both conditions are highly prevalent and have a negative impact on the prognosis of BD. Therefore, a systematic approach is needed, based on accurate measurement of a patient's smoking habits and their risk of suicidal behavior, in order to establish an appropriate therapeutic plan.

Additional information

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors and was registered on PROSPERO with the CRD42022301570 on January 21th 2022.

Oxidative stress parameters and antioxidants in adults with unipolar or bipolar depression versus healthy controls: Systematic review and meta-analysis

BACKGROUND

To study differences in oxidative stress markers and antioxidants among patients with bipolar depression (BPD) and unipolar depression (UPD).

METHODS

Data sources. Electronic MEDLINE/PubMed/Cochrane Library/Scopus/TripDatabase database search until 30/06/2021.

STUDY SELECTION

Included were articles comparing antioxidant or oxidative stress markers between adults with BPD or UPD and healthy controls (HCs).

DATA EXTRACTION

Two authors extracted data independently. Random effects meta-analysis, calculating standardized mean differences for results from ≥3 studies.

RESULTS

Oxidative stress markers reported in 40 studies -1 published repeatedly- (UPD, studies = 30 n = 3072; their HCs, n = 2856; BPD, studies = 11 n = 393; their HCs, n = 540; with 1 study reporting on both UPD and BPD) included thiobarbituric acid reactive substances (TBARS), antioxidant uric acid and antioxidant-enhancing enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPX). Compared with HCs, UPD and BPD were associated with significantly higher levels of TBARS, without differences between UPD and BPD (P = 0.11). Compared with HCs, UPD and BPD did not differ regarding the activity of the CAT (P = 0.28), SOD (P = 0.87) and GPX (P = 0.25) enzymes. However, uric acid levels were significantly higher vs HCs in BPD than in UPD among adult patients (P = 0.004). Results were heterogenous, which, for some parameters, decreased after stratification by the blood source (serum, plasma red blood cells, whole blood).

LIMITATIONS

The main limitations are the small number of studies/participants in the BPD subgroup, and heterogeneity of the results.

SUMMATIONS

Both BPD and UPD may be associated with an impaired oxidative stress balance, with significantly higher uric acid levels vs. HCs in UPD than in BPD.

A Systematic Review of Genetic Polymorphisms Associated with Bipolar Disorder Comorbid to Substance Abuse

It is currently unknown which genetic polymorphisms are involved in substance use disorder (SUD) comorbid with bipolar disorder (BD). The research on polymorphisms in BD comorbid with SUD (BD + SUD) is summarized in this systematic review. We looked for case-control studies that genetically compared adults and adolescents with BD and SUD, healthy controls, and BD without SUD. PRISMA was used to create our protocol, which is PROSPERO-registered (identification: CRD4221270818). The following bibliographic databases were searched indefinitely until December 2021 to identify potentially relevant articles: PubMed, PsycINFO, Scopus, and Web of Science. This systematic review, after the qualitative analysis of the study selection, included 17 eligible articles. In the selected studies, 66 polymorphisms in 29 genes were investigated. The present work delivers a group of potentially valuable genetic polymorphisms associated with BD + SUD: rs11600996 (ARNTL), rs228642/rs228682/rs2640909 (PER3), PONQ192R (PON1), rs945032 (BDKRB2), rs1131339 (NR4A3), and rs6971 (TSPO). It is important to note that none of those findings have been confirmed by two or more studies; thus, we believe that all the polymorphisms identified in this review require additional evidence to be confirmed.

Circulating miRNAs as Potential Biomarkers for Patient Stratification in Bipolar Disorder: A Combined Review and Data Mining Approach

Bipolar disorder is a debilitating psychiatric condition that is shaped in a concerted interplay between hereditary and triggering risk factors. Profound depression and mania define the disorder, but high clinical heterogeneity among patients complicates diagnosis as well as pharmacological intervention. Identification of peripheral biomarkers that capture the genomic response to the exposome may thus progress the development of personalized treatment. MicroRNAs (miRNAs) play a prominent role in of post-transcriptional gene regulation in the context of brain development and mental health. They are coordinately modulated by multifarious effectors, and alteration in their expression profile has been reported in a variety of psychiatric conditions. Intriguingly, miRNAs can be released from CNS cells and enter circulatory bio-fluids where they remain remarkably stable. Hence, peripheral circulatory miRNAs may act as bio-indicators for the combination of genetic risk, environmental exposure, and/or treatment response. Here we provide a comprehensive literature search and data mining approach that summarize current experimental evidence supporting the applicability of miRNAs for patient stratification in bipolar disorder.

Expression of PON1, PON2, PON3 and MPO Genes in Patients with Depressive Disorders

Background: Taking into account the role of oxidative stress in neurodegeneration, we sought to evaluate the expression of genes for select enzymes with antioxidant properties (paraoxonases PON1, PON2 and PON3 and myeloperoxidase MPO) at the mRNA and protein levels in patients with depressive disorders. We further sought to determine the impact of oxidative stress in the etiopathogenesis of this group of mood disorders. Methods: A total of 290 subjects (190 depressed patients, 100 healthy controls) took part in the study. Sociodemographic and clinical data were collected. The severity of depressive symptoms was assessed using the Hamilton Depression Rating Scale (HDRS). Venous blood was collected. RT-PCR was used to assess gene expression at the mRNA level, while enzyme-linked immunosorbent assay (ELISA) was used to assess gene expression at the protein level. Results: The expression of the PON2 and PON3 genes at the protein level was significantly higher in depressive patients than in healthy controls. mRNA expression of the PON1, PON2 and PON3 genes was slightly higher in patients with depressive disorders than in the control group, however, this relationship was not statistically significant. On the other hand, the expression of the MPO gene at both mRNA and protein levels was significantly lower in patients with depressive disorder than in the control group. Conclusions: Our results are not in agreement with many studies on enzymes involved in maintaining oxidative balance. Our findings may not support the utility of paraoxonases (PON) or myeloperoxidase (MPO) as promising biomarker candidates of depression pending larger and well controlled studies.

Inflammatory Markers in Substance Use and Mood Disorders: A Neuroimaging Perspective

Chronic exposure to addictive drugs in substance use disorders and stressors in mood disorders render the brain more vulnerable to inflammation. Inflammation in the brain, or neuroinflammation, is characterized by gliosis, microglial activation, and sustained release of cytokines, chemokines, and pro-inflammatory factors compromising the permeability of the blood-brain barrier. There is increased curiosity in understanding how substance misuse and/or repeated stress exposure affect inflammation and contribute to abnormal neuronal activity, altered neuroplasticity, and impaired cognitive control, which eventually promote compulsive drug-use behaviors and worsen mood disorders. This review will emphasize human imaging studies to explore the link between brain function and peripheral markers of inflammation in substance use disorders and mood disorders.

Intersections between Copper, β-Arrestin-1, Calcium, FBXW7, CD17, Insulin Resistance and Atherogenicity Mediate Depression and Anxiety Due to Type 2 Diabetes Mellitus: A Nomothetic Network Approach

Type 2 diabetes mellitus (T2DM) is frequently accompanied by affective disorders with a prevalence of comorbid depression of around 25%. Nevertheless, the biomarkers of affective symptoms including depression and anxiety due to T2DM are not well established. The present study delineated the effects of serum levels of copper, zinc, β-arrestin-1, FBXW7, lactosylceramide (LacCer), serotonin, calcium, magnesium on severity of depression and anxiety in 58 men with T2DM and 30 healthy male controls beyond the effects of insulin resistance (IR) and atherogenicity. Severity of affective symptoms was assessed using the Hamilton Depression and Anxiety rating scales. We found that 61.7% of the variance in affective symptoms was explained by the multivariate regression on copper, β-arrestin-1, calcium, and IR coupled with atherogenicity. Copper and LacCer (positive) and calcium and BXW7 (inverse) had significant specific indirect effects on affective symptoms, which were mediated by IR and atherogenicity. Copper, β-arrestin-1, and calcium were associated with affective symptoms above and beyond the effects of IR and atherogenicity. T2DM and affective symptoms share common pathways, namely increased atherogenicity, IR, copper, and β-arrestin-1, and lowered calcium, whereas copper, β-arrestin-1, calcium, LacCer, and FBXW7 may modulate depression and anxiety symptoms by affecting T2DM.

Shared metabolic and neuroimmune mechanisms underlying Type 2 Diabetes Mellitus and Major Depressive Disorder

Type 2 Diabetes Mellitus (T2DM) is a chronic metabolic disease with symptoms that go beyond the domain of glucose metabolism. In fact, research has shown that T2DM is accompanied by neurodegeneration and neuroinflammation. Interestingly, Major Depressive Disorder (MDD), a mood disorder characterized mainly by depressed mood and anhedonia is a key feature of T2DM. A body of evidence demonstrates that there are many shared neuroimmune mechanisms underlying the pathophysiology of T2DM and MDD. Therefore, here we review the state-of-art regarding the underlying factors common to both T2DM and MDD. Furthermore, we briefly discuss how depressive symptoms in diabetic patients could be tackled by using novel therapeutic approaches uncovered by these shared mechanisms. Understanding the comorbidity of depression in diabetic patients is essential to fully address T2DM pathophysiology and treatment.

Oxidative Stress Markers and Antioxidant Enzymes in Children and Adolescents with Depressive Disorder and Impact of Omega-3 Fatty Acids in Randomised Clinical Trial

Oxidative stress (OS) is thought to play a role in mental disorders. However, it is not clear whether the OS is the cause or consequence of the disorder. We investigated markers of oxidative stress (8-isoprostane (8-IsoP-U), lipoperoxides (LP), advanced oxidation protein products (AOPP) and nitrotyrosine (NT)) and antioxidant protection (Trolox equivalent antioxidant capacity (TEAC), activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) in 60 paediatric and adolescent patients with depressive disorder (DD) compared to healthy controls. The patients were divided into two groups (1:1). One group received an emulsion of omega-3 fatty acid (FA), and the other group an emulsion of sunflower oil with omega-6 FA for 12 weeks. The levels of 8-IsoP-U, AOPP and NT were increased, and GPx activity was decreased in patients compared to the controls. We found a significant positive correlation of the Children’s Depression Inventory score with NT and a negative correlation with TEAC, SOD and GPx. NT correlated positively with the baseline omega-6/omega-3 FA ratio and a negatively with SOD. A supplementation with omega-3 FA, but not with omega-6 FA, decreased 8-IsoP-U, AOPP, NT levels and increased TEAC and SOD activity. Our results suggest that NT may play a role in the pathophysiology of DD, while elevated isoprostane is likely caused by the high omega-6/omega-3 FA ratio. Omega-3 FA supplementation reduces oxidative stress in patients with DD. This study was registered with the ISRCTN registry (ISRCTN81655012).

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

Smoking and Neuropsychiatric Disease-Associations and Underlying Mechanisms

Despite extensive efforts to combat cigarette smoking/tobacco use, it still remains a leading cause of global morbidity and mortality, killing more than eight million people each year. While tobacco smoking is a major risk factor for non-communicable diseases related to the four main groups—cardiovascular disease, cancer, chronic lung disease, and diabetes—its impact on neuropsychiatric risk is rather elusive. The aim of this review article is to emphasize the importance of smoking as a potential risk factor for neuropsychiatric disease and to identify central pathophysiological mechanisms that may contribute to this relationship. There is strong evidence from epidemiological and experimental studies indicating that smoking may increase the risk of various neuropsychiatric diseases, such as dementia/cognitive decline, schizophrenia/psychosis, depression, anxiety disorder, and suicidal behavior induced by structural and functional alterations of the central nervous system, mainly centered on inflammatory and oxidative stress pathways. From a public health perspective, preventive measures and policies designed to counteract the global epidemic of smoking should necessarily include warnings and actions that address the risk of neuropsychiatric disease.

The lipid paradox in neuroprogressive disorders: Causes and consequences

Chronic systemic inflammation is associated with an increased risk of cardiovascular disease in an environment of low low-density lipoprotein (LDL) and low total cholesterol and with the pathophysiology of neuroprogressive disorders. The causes and consequences of this lipid paradox are explored. Circulating activated neutrophils can release inflammatory molecules such as myeloperoxidase and the pro-inflammatory cytokines interleukin-1 beta, interleukin-6 and tumour necrosis factor-alpha. Since activated neutrophils are associated with atherosclerosis and cardiovascular disease and with major depressive disorder, bipolar disorder and schizophrenia, it seems reasonable to hypothesise that the inflammatory molecules released by them may act as mediators of the link between systemic inflammation and the development of atherosclerosis in neuroprogressive disorders. This hypothesis is tested by considering the association at a molecular level of systemic inflammation with increased LDL oxidation; increased small dense LDL levels; increased lipoprotein (a) concentration; secretory phospholipase A₂ activation; cytosolic phospholipase A₂ activation; increased platelet activation; decreased apolipoprotein A1 levels and function; decreased paroxonase-1 activity; hyperhomocysteinaemia; and metabolic endotoxaemia. These molecular mechanisms suggest potential therapeutic targets.

PON1 polymorphisms can predict generalized anxiety and depressed mood in patients with multiple chemical sensitivity

Background: Multiple chemical sensitivity (MCS) is a chronic condition with somatic, cognitive and affective symptoms that follow contact with chemical agents at usually non toxic concentrations. We aimed to assess the role of genetic polymorphisms involved in oxidative stress on anxiety and depression in MCS. Materials & methods: Our study investigated the CAT rs1001179, MPO rs2333227, PON1 rs662 and PON1 rs705379 polymorphisms in MCS. Results: The AG genotype of the PON1 rs662 and the TT and CT genotypes of the PON1 rs705379 were involved in anxiety and depression. Discussion: These results are in line with existing evidence of PON1 involvement in MCS and suggest a further role of this gene in the exhibition of anxiety and depression in this disease.

Oxidative stress parameters and antioxidants in patients with bipolar disorder: Results from a meta-analysis comparing patients, including stratification by polarity and euthymic status, with healthy controls

OBJECTIVE

To investigate oxidative stress markers and antioxidants in bipolar disorder (BD).

METHODS

Electronic MEDLINE/PubMed/Cochrane-Library/Scopus/TripDatabase search until 06/30/2019 for studies comparing antioxidant or oxidative stress markers between BD and healthy controls (HCs). Standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated for ≥3 studies.

RESULTS

Forty-four studies (n = 3,767: BD = 1,979; HCs = 1,788) reported on oxidative stress markers malondialdehyde (MDA), thiobarbituric acid reactive substances (TBARS), and total nitrites; antioxidants glutathione (GSH), uric acid, and zinc; or antioxidantenhancing enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and GSH-transferase (GST). Compared with HCs, BD was associated with higher GST (P = .01), CAT (P = .02), nitrites (P < .0001), TBARS (P < .0001), MDA (P = .01), uric acid (P < .0001), and lower GSH (P = .006), without differences in SOD, GPX, and zinc. Compared to HCs, levels were higher in BD-mania for TBARS (P < .0001) and uric acid (P < .0001); in BD-depression for TBARS (P = .02); and BD-euthymia for uric acid (P = .03). Uric acid levels were higher in BD-mania vs BD-depression (P = .002), but not vs BD euthymia. TBARS did not differ between BD-mania and BD-depression. Medication-free BD-mania patients had higher SOD (P = .02) and lower GPX (P < .0001) than HCs. After treatment, BD did not differ from HCs regarding SOD and GPX.

CONCLUSIONS

Beyond a single biomarker of oxidative stress, the combination of several parameters appears to be more informative for BD in general and taking into account illness polarity. BD is associated with an imbalance in oxidative stress with some phase-specificity for uric acid and TBARS and possible treatment benefits for SOD and GPX. Future studies should take into account confounding factors that can modify oxidative stress status and simultaneously measure oxidative stress markers and antioxidants including different blood sources.

The role of high-density lipoprotein cholesterol, apolipoprotein A and paraoxonase-1 in the pathophysiology of neuroprogressive disorders

Lowered high-density lipoprotein (HDL) cholesterol has been reported in major depressive disorder, bipolar disorder, first episode of psychosis, and schizophrenia. HDL, its major apolipoprotein component, ApoA1, and the antioxidant enzyme paraoxonase (PON)1 (which is normally bound to ApoA1) all have anti-atherogenic, antioxidant, anti-inflammatory, and immunomodulatory roles, which are discussed in this paper. The paper details the pathways mediating the anti-inflammatory effects of HDL, ApoA1 and PON1 and describes the mechanisms leading to compromised HDL and PON1 levels and function in an environment of chronic inflammation. The molecular mechanisms by which changes in HDL, ApoA1 and PON1 might contribute to the pathophysiology of the neuroprogressive disorders are explained. Moreover, the anti-inflammatory actions of ApoM-mediated sphingosine 1-phosphate (S1P) signalling are reviewed as well as the deleterious effects of chronic inflammation and oxidative stress on ApoM/S1P signalling. Finally, therapeutic interventions specifically aimed at improving the levels and function of HDL and PON1 while reducing levels of inflammation and oxidative stress are considered. These include the so-called Mediterranean diet, extra virgin olive oil, polyphenols, flavonoids, isoflavones, pomegranate juice, melatonin and the Mediterranean diet combined with the ketogenic diet.

Prevalence and correlates of major depressive disorder: a systematic review

OBJECTIVES

Major depressive disorder (MDD) is one of the most disabling mental illnesses and it has a significant impact on society. This review aims to provide updated scientific evidence about the epidemiology of MDD.

METHODS

A systematic literature review of the PubMed and MEDLINE databases was performed to identify articles on the prevalence of MDD and its correlates. The search was restricted to manuscripts published between January 2001 and December 2018.

RESULTS

Sixty-three articles were included in the review. The lifetime prevalence of MDD ranged from 2 to 21%, with the highest rates found in some European countries and the lowest in some Asian countries. The main sociodemographic correlates were separated/divorced marital status and female gender. Child abuse, intimate partner violence, and comorbidity with other physical and mental disorders also were consistently associated with MDD across the reviewed studies.

CONCLUSIONS

MDD is a highly prevalent condition worldwide. There are remarkable interregional differences in the disorder's prevalence, as well as in certain sociodemographic correlates. MDD is also highly comorbid with physical and mental health problems.

Construction of a nitro-oxidative stress-driven, mechanistic model of mood disorders: A nomothetic network approach

Major depression is accompanied by increased IgM-mediated autoimmune responses to oxidative specific epitopes (OSEs) and nitric oxide (NO)-adducts. These responses were not examined in bipolar disorder type 1 (BP1) and BP2. IgM responses to malondialdehyde (MDA), phosphatidinylinositol, oleic acid, azelaic acid, and NO-adducts were determined in 35 healthy controls, and 47 major depressed (MDD), 29 BP1, and 25 BP2 patients. We also measured serum peroxides, IgG to oxidized LDL (oxLDL), and IgM/IgA directed to lipopolysaccharides (LPS). IgM responses to OSEs and NO-adducts (OSENO) were significantly higher in MDD and BP1 as compared with controls, and IgM to OSEs higher in MDD than in BP2. Partial Least Squares (PLS) analysis showed that 57.7% of the variance in the clinical phenome of mood disorders was explained by number of episodes, a latent vector extracted from IgM to OSENO, IgG to oxLDL, and peroxides. There were significant specific indirect effects of IgA/IgM to LPS on the clinical phenome, which were mediated by peroxides, IgM OSENO, and IgG oxLDL. Using PLS we have constructed a data-driven nomothetic network which ensembled causome (increased plasma LPS load), adverse outcome pathways (namely neuro-affective toxicity), and clinical phenome features of mood disorders in a data-driven model. Based on those feature sets, cluster analysis discovered a new diagnostic class characterized by increased plasma LPS load, peroxides, autoimmune responses to OSENO, and increased phenome scores. Using the new nomothetic network approach, we constructed a mechanistically transdiagnostic diagnostic class indicating neuro-affective toxicity in 74.3% of the mood disorder patients.

Lipid Profile, Lipoprotein Subfractions, and Fluidity of Membranes in Children and Adolescents with Depressive Disorder: Effect of Omega-3 Fatty Acids in a Double-Blind Randomized Controlled Study

Depressive disorder (DD) is a psychiatric disorder whose molecular basis is not fully understood. It is assumed that reduced consumption of fish and omega-3 fatty acids (FA) is associated with DD. Other lipids such as total cholesterol (TCH), LDL-, and HDL-cholesterols (LDL-CH, HDL-CH) also play a role in depression. The primary endpoint of the study was the effect of omega-3 FA on the severity of depression in children and adolescents. This study aimed to investigate the secondary endpoint, relationship between depressive disorder symptoms and lipid profile, LDL- and HDL-cholesterol subfractions, Paraoxonase 1 (PON1) activities, and erythrocyte membrane fluidity in 58 depressed children and adolescents (calculated by the statistical program on the effect size), as well as the effect of omega-3 FA on the monitored parameters. Depressive symptoms were assessed by the Children’s Depression Inventory (CDI), lipid profile by standard biochemical procedures, and LDL- and HDL-subfractions by the Lipoprint system. Basic biochemical parameters including lipid profile were compared with levels in 20 healthy children and were in the physiological range. Improvement of symptoms in the group supplemented with a fish oil emulsion rich in omega-3 FA in contrast to omega-6 FA (emulsion of sunflower oil) has been observed. We are the first to report that omega-3 FAs, but not omega-6 FA, increase large HDL subfractions (anti-atherogenic) after 12 weeks of supplementation and decrease small HDL subfractions (proatherogenic) in depressed children. We found a negative correlation between CDI score and HDL-CH and the large HDL subfraction, but not LDL-CH subfractions. CDI score was not associated with erythrocyte membrane fluidity. Our results suggest that HDL-CH and its subfractions, but not LDL-CH may play a role in the pathophysiology of depressive disorder. The study was registered under ISRCTN81655012.

The role of immune and oxidative pathways in menstrual cycle associated depressive, physio-somatic, breast and anxiety symptoms: Modulation by sex hormones

OBJECTIVE

To examine whether 1) immune and nitro-oxidative stress (IO&NS) biomarkers are associated with premenstrual syndrome (PMS); and 2) changes in IO&NS biomarkers during the menstrual cycle (MC) are associated with PMS symptoms and plasma estradiol and progesterone.

METHODS

This longitudinal study examined 41 women who completed the Daily Record of Severity of Problems (DRSP) rating scale during 28 consecutive days and assayed plasma levels of complement C3 and C4, highly sensitive C-reactive protein (hsCRP), haptoglobin (Hp), advanced oxidation protein products (AOPP), lipid hydroperoxides (LOOH), nitric oxide metabolites (NOx), total radical-trapping antioxidant parameter (TRAP), sulfhydryl (-SH) groups and the activity of paraoxonase (PON)1 at days 7 (D7), 14 (D14), 21 (D21) and 28 (D28) of the MC. MC Associated Syndrome (MCAS) was diagnosed when the summed DRSP score during the MC is >0.666 percentile.

RESULTS

All biomarkers, except hsCRP, showed significant alterations during the MC. Arylesterase (AREase) was lowered at D28, while LOOH increased at D14 and C4 at D21 in MCAS. Total DRSP scores were predicted by the combined effects of C4 (positively) and AREase and malondialdehyde (MDA) (both inversely associated). Progesterone lowered levels of LOOH, AOPP and C3 and estradiol lowered levels of Hp while both sex hormones increased 4-(chloromethyl)phenyl acetate (CMPA)ase and AREase activities and levels of -SH groups.

CONCLUSION

PMS/MCAS is not accompanied by a peripheral inflammatory response. Lowered MDA and antioxidant defenses and increased C4 may play a role in MC symptoms while sex hormones may have a protective effect against oxidative stress toxicity.

Beyond the looking glass: recent advances in understanding the impact of environmental exposures on neuropsychiatric disease

The etiologic pathways leading to neuropsychiatric diseases remain poorly defined. As genomic technologies have advanced over the past several decades, considerable progress has been made linking neuropsychiatric disorders to genetic underpinnings. Interest and consideration of nongenetic risk factors (e.g., lead exposure and schizophrenia) have, in contrast, lagged behind heritable frameworks of explanation. Thus, the association of neuropsychiatric illness to environmental chemical exposure, and their potential interactions with genetic susceptibility, are largely unexplored. In this review, we describe emerging approaches for considering the impact of chemical risk factors acting alone and in concert with genetic risk, and point to the potential role of epigenetics in mediating exposure effects on transcription of genes implicated in mental disorders. We highlight recent examples of research in nongenetic risk factors in psychiatric disorders that point to potential shared biological mechanisms-synaptic dysfunction, immune alterations, and gut-brain interactions. We outline new tools and resources that can be harnessed for the study of environmental factors in psychiatric disorders. These tools, combined with emerging experimental evidence, suggest that there is a need to broadly incorporate environmental exposures in psychiatric research, with the ultimate goal of identifying modifiable risk factors and informing new treatment strategies for neuropsychiatric disease.

Frontocingulate Dysfunction Is Associated with Depression and Decreased Serum PON1 in Methamphetamine-Dependent Patients

INTRODUCTION

Studies have been reported that frequent use of methamphetamine (MA) is associated with brain function impairment, mood disorders and excessive free radical production accompanied by the decreased level of the antioxidant response elements, but no study investigated their correlations simultaneously. In the current study, the correlation of brain function, depression and anxiety levels, and the serum levels of PON1 (an antioxidant) in MA-dependent patients were investigated.

METHODS

Nineteen active MA abusers and 18 control subjects performed color-word Stroop task during fMRI and the state of their depression, anxiety, and stress were measured by the Depression, Anxiety and Stress Scale-21 Items (DASS-21) questionnaire. Their blood samples were collected to measure the level of PON1 by the human enzyme-linked immunosorbent assay (ELISA) kit and its correlation with the measured variables was studied.

RESULTS

Analysis of fMRI findings showed frontocingulate dysfunction in Stroop effect condition, including left anterior cingulate cortex, paracingulate gyrus, superior frontal gyrus, and frontal pole in MA-dependent patients, which was associated with a higher level of depression and decreased level of serum PON1 in these patients.

DISCUSSION

The results of the current study showed that MA-dependency is associated with frontocingulate dysfunction, decreased serum PON1 concentration, and increased depression/anxiety, which is worth to be more studied to elucidate their roles in the pathophysiology of MA addiction.

Gene-Environment Interactions in Psychiatry: Recent Evidence and Clinical Implications

PURPOSE OF REVIEW

We identify the recent evidence for gene-by-environment interaction studies in relation to psychiatric disorders. We focus on the key genotypic data as well as environmental exposures and how they interact to predict psychiatric disorders and psychiatric symptomatology. We direct our focus on the psychiatric outcomes that were focused on by the Psychiatric Genetics Consortium.

RECENT FINDINGS

Many of the studies focus on candidate gene approaches, with most of the studies drawing upon previous literature to decide the genes of interest. Other studies used a genome-wide approach. While some studies demonstrated positive replication of previous findings, replication is still an issue within gene-by-environment interaction studies. Gene-by-environment interaction research in psychiatry globally suggests some susceptibility to environmental exposures based on genotype; however, greater clarity is needed around the idea that genetic risk may not be disorder specific.

Shared genetic risk factors for depression and stroke

BACKGROUND

The comorbidity of major depressive disorder (MDD) and stroke are common in clinic. There is a growing body of evidence suggesting a bi-directional relationship between stroke and depression. However, the mechanisms underlying the relationship between MDD and stroke are poorly investigated. Considering that both MDD and stroke can be heritable and are influenced by multiple risk genes, shared genetic risk factors between MDD and stroke may exist.

OBJECTIVE

The objective is to review the existing evidence for common genetic risk factors for both MDD and stroke and to outline the possible pathophysiological mechanisms mediating this association.

METHODS

A systematic review and meta-analysis was performed. Gene association studies regarding stroke and depression were searched in the database PubMed, CNKI, and Chinese Biomedical Literature Database before December 2018. Statistical analysis was performed using the software Revman 5.3.

RESULTS

Genetic polymorphisms of 4 genes, methylenetetrahydrofolate reductase (MTHFR) and apolipoprotein E (ApoE) have been demonstrated to associate with the increased risk for both MDD and stroke, while the association between identified polymorphisms in angiotensin converting enzyme (ACE) and serum paraoxonase (PON1) with depression is still under debate, for the existing studies are insufficient in sample size. These results suggest the possible pathophysiological mechanisms that are common to these two disorders, including immune-inflammatory imbalance, increased oxidative and nitrative stress, dysregulation of lipoprotein and lipid metabolism, and changes of cerebrovascular morphology and function. Other associated genes with few or conflicting results have also been included, and a few studies have investigated the effects of the described polymorphisms on MDD and stroke comorbidity, such as post stroke depression.

CONCLUSION

These findings suggest that shared genetic pathways may contribute to the comorbidity of MDD and stroke. Studies to evaluate the shared genetic variations between MDD and stroke may provide insights into the molecular mechanisms that trigger disease progression.

Lowered PON1 activities are strongly associated with depression and bipolar disorder, recurrence of (hypo)mania and depression, increased disability and lowered quality of life

Objectives: Mood disorders (MDs) frequently co-exist with cardiovascular disease (CVD) and immune-inflammatory and oxidative stress are important shared pathophysiological pathways. Even though there has been an extensive investigation of the enzyme paraoxonase 1 (PON1) as a biomarker of susceptibility for CVD, there are few reports studying PON1 in MDs. The aim of this study was to determine the association between PON1 activities as well as functional genotypes and MD diagnosis, clinical characteristics and outcomes. Methods: PON1 activities and functional genotypes were assayed in 58 bipolar disorder (BD) and 32 major depressed patients (MDD) and compared with 59 controls. Results: Our findings show significantly lower PON1 total and CMPAase activities in MDs, which are partly related to the number of previous depressive and manic episodes. Lowered CMPAase activity is associated with a worse outcome of MDs as indicated by lowered quality of life (WHOQoL-BREF scale) and increased disability in the Sheeham scale. Conclusions: We hypothesise that lowered PON1 total and CMPAase activities may play a role in the pathophysiology of MDs by lowering antioxidant defences thereby increasing the risk of lipid peroxidation and inflammation; lowered inhibition of quorum-sensing lactones thereby increasing bacterial proliferation; and attenuated homocysteine thiolactone catabolism which may trigger immune-inflammatory response and/or induce neurotoxicity.

Peripheral Oxidative Stress Markers in Patients with Bipolar Disorder during Euthymia and in Siblings

AIMS

Oxidative stress is increased during the acute phases of bipolar disorder (BD). Our aim here was to analyze oxidative stress biomarkers in patients with BD during euthymia and their siblings.

METHOD

A cross-sectional study was performed in euthymic patients with BD-I (n=48), unaffected siblings (n=23) and genetically unrelated healthy controls (n=21). Protein carbonyl content (PCC), total antioxidant capacity (TRAP), lipid peroxidation (TBARS) and uric acid were measured as biomarkers of oxidative stress in blood.

RESULTS

The antioxidant capacity (TRAP) was lower (p<0.001) in patients with BD compared to their siblings and controls, whereas no differences were observed in PCC, TBARS or uric acid. In patients, the concentrations of TRAP and TBARS were positively associated with the dose of valproic acid (p<0.05 and p<0.001, respectively). The concentrations of these biomarkers were not significantly associated with any of socio-demographic and clinical variables.

CONCLUSION

A selective reduction in antioxidant capacity is present in BD during euthymia state, whereas other markers of oxidative stress are unaltered during euthymia. Siblings did not show any alterations in oxidative stress biomarkers. Oxidative stress might represent a state-dependent marker in BD. The association between treatment with valproic acid and oxidative stress markers in euthymia deserves further studies.

Why Should Psychiatrists and Neuroscientists Worry about Paraoxonase 1?

BACKGROUND

Nitro-oxidative stress (NOS) has been implicated in the pathophysiology of psychiatric disorders. The activity of the polymorphic antioxidant enzyme paraoxonase 1 (PON1) is altered in diseases where NOS is involved. PON1 activity may be estimated using different substrates some of which are influenced by PON1 polymorphisms.

OBJECTIVES

1) to review the association between PON1 activities and psychiatric diseases using a standardized PON1 substrate terminology in order to offer a state-of-the-art review; and 2) to review the efficacy of different strategies (nutrition, drugs, lifestyle) to enhance PON1 activities.

METHODS

The PubMed database was searched using the terms paraoxonase 1 and psychiatric diseases. Moreover, the database was also searched for clinical trials investigating strategies to enhance PON1 activity.

RESULTS

The studies support decreased PON1 activity as determined using phenylacetate (i.e., arylesterase or AREase) as a substrate, in depression, bipolar disorder, generalized anxiety disorder (GAD) and schizophrenia, especially in antipsychotic-free patients. PON1 activity as determined with paraoxon (i.e., POase activity) yields more controversial results, which can be explained by the lack of adjustment for the Q192R polymorphism. The few clinical trials investigating the influence of nutritional, lifestyle and drugs on PON1 activities in the general population suggest that some polyphenols, oleic acid, Mediterranean diet, no smoking, being physically active and statins may be effective strategies that increase PON1 activity.

CONCLUSION

Lowered PON1 activities appear to be a key component in the ongoing NOS processes that accompany affective disorders, GAD and schizophrenia. Treatments increasing attenuated PON1 activity could possibly be new drug targets for treating these disorders.

A review of the neurobiological underpinning of comorbid substance use and mood disorders

BACKGROUND

There is evidence that substance use disorders and other mental disorders may have shared biological mechanisms. However, the neurobiological basis of this comorbidity remains only partially explained. This review describes the historical evolution of the dual disorders concept and approach, and reviews the existing literature on neurobiological findings specifically regarding comorbid substance use and mood disorders.

METHODS

Searches were conducted using PubMed and Scopus in December 2017. A Boolean search was performed using combinations of "dual diagnosis" or "dual disorder" or "depression" or "bipolar" or "affective disorder" or "mood disorder" and "substance use" or "substance abuse" and "neurobiology" or "functional neuroimaging" or "genetics" or "neurotransmitters" or "neuroendocrinology" in the title or abstract, or as keywords, using no language restriction.

RESULTS

32 studies met the inclusion criteria. We found robust evidence for involvement of the neurotransmitters dopamine, GABA and glutamate and their receptors, as well as by the central corticotrophin-releasing hormone, hypothalamic-pituitary-adrenal axis activation, oxidative stress and inflammation. Recent studies focusing on neuroimaging and genetics have not shown consistent results.

LIMITATIONS

Only two search tools were used; most identified studies excluded the population of interest (comorbid mood and substance abuse disorders).

CONCLUSIONS

The neurobiological relevance for the occurrence of comorbid mood and substance abuse disorders has not been fully elucidated. Considering the high levels of individuals who experience comorbidity in these areas as well as the negative associated outcomes, this is clearly an area that requires further in-depth investigation. Furthermore, findings from this area can help to inform drug abuse prevention and intervention efforts, and especially how they relate to populations with psychiatric symptoms.

Early Life Trauma Predicts Affective Phenomenology and the Effects are Partly Mediated by Staging Coupled with Lowered Lipid-Associated Antioxidant Defences

Background Early life trauma (ELT) may drive mood disorder phenomenology, nitro-oxidative pathways and impairments in semantic memory. There are no data regarding the impact of ELT on affective phenomenology and whether these pathways are mediated by staging or lowered lipid-associated antioxidant defences. Methods This study examined healthy controls (n=54) and patients with affective disorders including major depression, bipolar disorder and anxiety disorders (n=118). ELT was assessed using the Child Trauma Questionnaire. In addition, we measured affective phenomenology and assayed advanced oxidation protein products; malondialdehyde, paraoxonase 1 (CMPAase) activity, high-sensitivity C-reactive protein (hsCRP), and high-density lipoprotein (HDL) cholesterol. Results ELT was associated into with increased risk for mood and comorbid anxiety disorders and a more severe phenomenology, including staging characteristics, depression and anxiety severity, suicidal behaviours, type of treatments, disabilities, body mass index, smoking behaviour and hsCRP, as well as lowered health-related quality of life, antioxidant defences and semantic memory. The number of mood episodes and CMPAase/HDL-cholesterol levels could be reliably combined into a new vulnerability staging-biomarker index, which mediates in part the effects of ELT on affective phenomenology and oxidative stress. Moreover, the effects of female sex on mood disorders and affective phenomenology are mediated by ELT. Discussion The cumulative effects of different ELT drive many aspects of affective phenomenology either directly or indirectly through effects of staging and/or lipid-associated antioxidant defences. The results show that children, especially girls, with ELT are at great risk to develop mood disorders and more severe phenotypes of affective disorders.

In major affective disorders, early life trauma predict increased nitro-oxidative stress, lipid peroxidation and protein oxidation and recurrence of major affective disorders, suicidal behaviors and a lowered quality of life

Early life trauma (ELT) may increase the risk towards bipolar disorder (BD) and major depression (MDD), disorders associated with activated neuro-oxidative and neuro-nitrosative stress (O&NS) pathways. It has remained elusive whether ELTs are associated with O&NS and which ELTs are associated with distinct affective disorder phenotypes. This case-control study examined patients with BD (n = 68) and MDD (n = 37) and healthy controls (n = 66). The Child Trauma Questionnaire (CTQ) was used to assess specific ELT. We measured malondialdehyde (MDA), lipid hydroperoxides (LOOH), superoxide dismutase (SOD), catalase, advanced oxidation protein products (AOPP); NO metabolites (NOx), paraoxonase 1 activity, zinc, albumin, high density lipoprotein cholesterol and -SH groups and computed z-unit weighted composite scores. Physical neglect significantly predicts higher z-unit weighted composite scores of LOOH+SOD, LOOH+SOD+NOx, LOOH+SOD+NOx + MDA and LOOH+SOD+NOx + AOPP. Sexual abuse was associated with a significantly lower composite score of zinc+albumin+SH. Emotional abuse was associated with severity of depression and anxiety, number of depressive and manic episodes, alcohol and hypnotics use, lifetime suicidal behavior and lowered quality of life. Sexual abuse was associated with an increased risk towards BD, but not MDD. ELT, especially physical neglect, may drive increased (nitro-)oxidative stress coupled with lipid and protein oxidation, which - together with emotional abuse - may play a role in severity of illness, lowered quality of life and MDD. ELTs are also associated with the onset of BD, but this link did not appear to be related to activated O&NS pathways. These novel findings deserve confirmation in prospective studies.

Interactions Between Variation in Candidate Genes and Environmental Factors in the Etiology of Schizophrenia and Bipolar Disorder: a Systematic Review

Schizophrenia and bipolar disorder (BD) are complex and multidimensional disorders with high heritability rates. The contribution of genetic factors to the etiology of these disorders is increasingly being recognized as the action of multiple risk variants with small effect sizes, which might explain only a minor part of susceptibility. On the other site, numerous environmental factors have been found to play an important role in their causality. Therefore, in recent years, several studies focused on gene × environment interactions that are believed to bridge the gap between genetic underpinnings and environmental insults. In this article, we performed a systematic review of studies investigating gene × environment interactions in BD and schizophrenia spectrum phenotypes. In the majority of studies from this field, interacting effects of variation in genes encoding catechol-O-methyltransferase (COMT), brain-derived neurotrophic factor (BDNF), and FK506-binding protein 5 (FKBP5) have been explored. Almost consistently, these studies revealed that polymorphisms in COMT, BDNF, and FKBP5 genes might interact with early life stress and cannabis abuse or dependence, influencing various outcomes of schizophrenia spectrum disorders and BD. Other interactions still require further replication in larger clinical and non-clinical samples. In addition, future studies should address the direction of causality and potential mechanisms of the relationship between gene × environment interactions and various categories of outcomes in schizophrenia and BD.

Generalized Anxiety Disorder (GAD) and Comorbid Major Depression with GAD Are Characterized by Enhanced Nitro-oxidative Stress, Increased Lipid Peroxidation, and Lowered Lipid-Associated Antioxidant Defenses

Accumulating evidence shows that nitro-oxidative pathways play an important role in the pathophysiology of major depressive disorder (MDD) and bipolar disorder (BD) and maybe anxiety disorders. The current study aims to examine superoxide dismutase (SOD1), catalase, lipid hydroperoxides (LOOH), nitric oxide metabolites (NOx), advanced oxidation protein products (AOPP), malondialdehyde (MDA), glutathione (GSH), paraoxonase 1 (PON1), high-density lipoprotein cholesterol (HDL), and uric acid (UA) in participants with and without generalized anxiety disorder (GAD) co-occurring or not with BD, MDD, or tobacco use disorder. Z unit-weighted composite scores were computed as indices of nitro-oxidative stress driving lipid and protein oxidation. SOD1, LOOH, NOx, and uric acid were significantly higher and HDL and PON1 significantly lower in participants with GAD than in those without GAD. GAD was more adequately predicted by increased SOD + LOOH + NOx and lowered HDL + PON1 composite scores. Composite scores of nitro-oxidative stress coupled with aldehyde and AOPP production were significantly increased in participants with comorbid GAD + MDD as compared with all other study groups, namely MDD, GAD + BD, BD, GAD, and healthy controls. In conclusion, GAD is characterized by increased nitro-oxidative stress and lipid peroxidation and lowered lipid-associated antioxidant defenses, while increased uric acid levels in GAD may protect against aldehyde production and protein oxidation. This study suggests that increased nitro-oxidative stress and especially increased SOD1 activity, NO production, and lipid peroxidation as well as lowered HDL-cholesterol and PON1 activity could be novel drug targets for GAD especially when comorbid with MDD.

Are there differences in lipid peroxidation and immune biomarkers between major depression and bipolar disorder: Effects of melancholia, atypical depression, severity of illness, episode number, suicidal ideation and prior suicide attempts

BACKGROUND

There is evidence that major depression (MDD) and bipolar disorder (BD) are accompanied by activated immune & oxidative (I&O) pathways.

METHODS

To compare I&O biomarkers between MDD and BD we assessed serum levels of thiobarbituric acid reactive substances (TBARS; a lipid peroxidation marker), soluble interleukin-2 receptor (sIL-2R), sIL-6R, IL-α, sIL-1R antagonist (sIL-1RA), tumor necrosis factor receptor 60kDa/80kDa (sTNFR60/R80) in 114 MDD and 133 BD patients, and 50 healthy controls. We computed z-unit weighted indices reflecting the 5 cytokine receptor levels (zCytR), cell-mediated immunity (zCMI) and I&O pathways (zCMI+TBARS).

RESULTS

There are no significant differences in biomarkers between MDD and BD. BD/MDD with atypical features is characterized by increased sIL-6R and TBARS, whereas melancholia is associated with higher TBARS and lower sTNFR60 levels. Severity of illness, as measured with the Hamilton Depression Rating Scale, is correlated with increased sIL-6R, sTNFR80, TBARS, zCytR and zCMI+TBARS. The number of episodes the year prior to blood sampling is positively associated with sTNFR80, TBARS, zCMI, zCMI+TBARS, while number of hospitalizations is positively associated with sIL-1RA. Prior suicidal attempts are associated with increased sIL-1RA, IL-1α, zCMI, TBARS and zCMI+TBARS, while TBARS is associated with current suicidal ideation.

CONCLUSIONS

There are no I&O biomarker differences between MDD and BD. Atypical depression is associated with increased IL-6 trans-signaling and lipid peroxidation. Severity of depression, number of episodes and suicidal attempts are associated with activated I&O pathways. Increased TBARS is the single best predictor of BD/MDD, atypical depression, melancholia and current suicidal ideation.

Youth Depression Alleviation-Augmentation with an anti-inflammatory agent (YoDA-A): protocol and rationale for a placebo-controlled randomized trial of rosuvastatin and aspirin

AIM

There is growing support for the role of inflammation and oxidative stress in the pathophysiology of major depressive disorder (MDD). This has led to the development of novel strategies targeting inflammation in the treatment of depression. Rosuvastatin and aspirin have well-documented, anti-inflammatory and antioxidant properties. The aim of the Youth Depression Alleviation: Augmentation with an anti-inflammatory agent (YoDA-A) study is to determine whether individuals receiving adjunctive anti-inflammatory agents, aspirin and rosuvastatin experience a reduction in the severity of MDD compared with individuals receiving placebo.

METHODS

YoDA-A is a 12-week triple-blind, randomized controlled trial funded by the National Health and Medical Research Council, Australia. Participants aged 15-25, with moderate-to-severe MDD, are allocated to receive either 10 mg/day rosuvastatin, 100 mg/day aspirin, or placebo, in addition to treatment as usual. Participants are assessed at baseline and at weeks 4, 8, 12 and 26. The primary outcome is change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to week 12.

RESULTS

The study is planned to be completed in 2017. At date of publication, 85 participants have been recruited.

CONCLUSION

Timely and targeted intervention for youth MDD is crucial. Given the paucity of new agents to treat youth MDD, adjunctive trials are not only pragmatic and 'real-world', but additionally aim to target shortfalls in conventional medications. This study has the potential to first provide two new adjunctive treatment options for youth MDD; aspirin and rosuvastatin. Second, this study will serve as proof of principle of the role of inflammation in MDD.

Add-on Treatment with Curcumin Has Antidepressive Effects in Thai Patients with Major Depression: Results of a Randomized Double-Blind Placebo-Controlled Study

Activation of immune-inflammatory and oxidative-nitrosative (IO&NS) stress pathways plays a role in major depression (MDD). Evidence suggests that curcumin (500-1000 mg/day), a polyphenol with strong anti-IO&NS properties, may have efficacy either as monotherapy or as an adjunctive treatment for depression. Further controlled trials with extended treatment periods (> 8 weeks) and higher curcumin doses are warranted. This 12-week study was carried out to examine the effects of adjunctive curcumin for the treatment of MDD. In this double-blind, placebo-controlled trial, 65 participants with MDD were randomized to receive either adjunctive curcumin (increasing dose from 500 to 1500 mg/day) or placebo for 12 weeks. Four weeks after the active treatment phase, a follow-up visit was conducted at week 16. Assessments of the primary, i.e., the Montgomery-Asberg Depression Rating Scale (MADRS), and secondary, i.e., the Hamilton Anxiety Rating Scale (HAM-A), outcome measures were rated at baseline and 2, 4, 8, 12, and 16 weeks later. Curcumin was more efficacious than placebo in improving MADRS scores with significant differences between curcumin and placebo emerging at weeks 12 and 16. The effects of curcumin were more pronounced in males compared to females. There were no statistically significant treatment-emerging adverse effects and no significant effects of curcumin on blood chemistry and ECG measurements. Adjunctive curcumin has significant antidepressant effects in participants with MDD as evidenced by significant benefits occurring 12 and 16 weeks after treatment initiation. Curcumin administration was safe and well-tolerated even when combined with antidepressants. Future trials should include treatment-by-sex interactions to examine putative antidepressant effects of immune-modifying compounds.

Activated neuro-oxidative and neuro-nitrosative pathways at the end of term are associated with inflammation and physio-somatic and depression symptoms, while predicting outcome characteristics in mother and baby

OBJECTIVES

To examine oxidative & nitrosative stress (O&NS) biomarkers at the end of term in relation to perinatal affective symptoms, neuro-immune biomarkers and pregnancy-related outcome variables.

METHODS

We measured plasma advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), total radical trapping antioxidant parameter (TRAP), -sulfhydryl (-SH), peroxides (LOOH) and paraoxonase (PON)1 activity in pregnant women with and without prenatal depression and non-pregnant controls.

RESULTS

Pregnancy is accompanied by significantly increased AOPP and NOx, and lowered TRAP, -SH and LOOH. Increased O&NS and lowered LOOH and -SH levels are associated with prenatal depressive and physio-somatic symptoms (fatigue, pain, dyspepsia, gastro-intestinal symptoms). Increased AOPP and NOx are significantly associated with lowered -SH, TRAP and zinc, and with increased haptoglobin and C-reactive protein levels. Increased O&NS and lowered TRAP and PON 1 activity, at the end of term predict mother (e.g. hyperpigmentation, labor duration, caesarian section, cord length, breast milk flow) and baby (e.g. sleep and feeding problems) outcome characteristics.

CONCLUSIONS

Pregnancy is accompanied by interrelated signs of O&NS, lowered antioxidant defenses and activated neuro-immune pathways. Increased O&NS at the end of term is associated with perinatal depressive and physio-somatic symptoms and may predict obstetric and behavioral complications in mother and baby.

Organophosphate pesticides and PON1 L55M in Parkinson's disease progression

BACKGROUND

Parkinson's disease (PD) has motor and non-motor features that contribute to its phenotype and functional decline. Organophosphate (OP) pesticides and PON1 L55M, which influences OP metabolism, have been implicated in multiple mechanisms related to neuronal cell death and may influence PD symptom progression.

OBJECTIVE

To investigate whether ambient agricultural OP exposure and PON1 L55M influence the rate of motor, cognitive, and mood-related symptom progression in PD.

METHODS

We followed a longitudinal cohort of 246 incident PD patients on average over 5years (7.5years after diagnosis), repeatedly measuring symptom progression with the Mini-Mental State Exam (MMSE), Unified Parkinson's Disease Rating Scale (UPDRS), and Geriatric Depressive Scale (GDS). OP exposures were generated with a geographic information system (GIS) based exposure assessment tool. We employed repeated-measures regression to assess associations between OP exposure and/or PON1 L55M genotype and progression.

RESULTS

High OP exposures were associated with faster progression of motor (UPDRS β=0.24, 95% CI=-0.01, 0.49) and cognitive scores (MMSE β=-0.06, 95% CI=-0.11, -0.01). PON1 55MM was associated with faster progression of motor (UPDRS β=0.28, 95% CI=0.08, 0.48) and depressive symptoms (GDS β=0.07; 95% CI=0.01, 0.13). We also found the PON1 L55M variant to interact with OP exposures in influencing MMSE cognitive scores (β=-1.26, 95% CI=-2.43, -0.09).

CONCLUSION

Our study provides preliminary support for the involvement of OP pesticides and PON1 in PD-related motor, cognitive, or depressive symptom progression. Future studies are needed to replicate findings and examine whether elderly populations generally are similarly impacted by pesticides or PON1 55M genotypes.

Increased Root Canal Endotoxin Levels are Associated with Chronic Apical Periodontitis, Increased Oxidative and Nitrosative Stress, Major Depression, Severity of Depression, and a Lowered Quality of Life

Evidence indicates that major depression is accompanied by increased translocation of gut commensal Gram-negative bacteria (leaky gut) and consequent activation of oxidative and nitrosative (O&NS) pathways. This present study examined the associations among chronic apical periodontitis (CAP), root canal endotoxin levels (lipopolysaccharides, LPS), O&NS pathways, depressive symptoms, and quality of life. Measurements included advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), lipid peroxides (LOOH), -sulfhydryl (SH) groups, total radical trapping antioxidant parameter (TRAP), and paraoxonase (PON)1 activity in participants with CAP, with and without depression, as well as healthy controls (no depression, no CAP). Root canal LPS levels were positively associated with CAP, clinical depression, severity of depression (as measured with the Hamilton Depression Rating Scale (HDRS) and the Beck Depression Inventory) and O&NS biomarkers, especially NOx and TRAP. CAP-related depression was accompanied by increased levels of NOx, LOOH, AOPP, and TRAP. In CAP participants, there was a strong correlation (r = 0.734, p < 0.001) between root canal LPS and the HDRS score. There were significant and positive associations between CAP or root canal endotoxin with the vegetative and physio-somatic symptoms of the HDRS as well as a significant inverse association between root canal endotoxin and quality of life with strong effects on psychological, environmental, and social domains. It is concluded that increased root canal LPS accompanying CAP may cause depression and a lowered quality of life, which may be partly explained by activated O&NS pathways, especially NOx thereby enhancing hypernitrosylation and thus neuroprogressive processes. Dental health and "leaky teeth" may be intimately linked to the etiology and course of depression, while significantly impacting quality of life.

Altered lipid peroxidation markers are related to post-traumatic stress disorder (PTSD) and not trauma itself in earthquake survivors

The traumatic life events, including earthquakes, war, and interpersonal conflicts, cause a cascade of psychological and biological changes known as post-traumatic stress disorder (PTSD). Malondialdehyde (MDA) is a reliable marker of lipid peroxidation, and paraoxonase is a known antioxidant enzyme. The aims of this study were to investigate the relationship between earthquake trauma, PTSD effects on oxidative stress and the levels of serum paraoxonase 1 (PON1) enzyme activity, and levels of serum MDA. The study was carried out on three groups called: the PTSD group, the traumatized with earthquake exercise group, and healthy control group, which contained 32, 31, and 38 individuals, respectively. Serum MDA levels and PON1 enzyme activities from all participants were measured, and the results were compared across all groups. There were no significant differences between the PTSD patients and non-PTSD earthquake survivors in terms of the study variables. The mean PON1 enzyme activity from PTSD patients was significantly lower, while the mean MDA level was significantly higher than that of the healthy control group (p < 0.01 for both measurements). Similarly, earthquake survivors who did not develop PTSD showed higher MDA levels and lower PON1 activity when compared to healthy controls. However, the differences between these groups did not reach a statistically significant level. Increased MDA level and decreased PON1 activity measured in PTSD patients after earthquake and may suggest increased oxidative stress in these patients. The nonsignificant trends that are observed in lipid peroxidation markers of earthquake survivors may indicate higher impact of PTSD development on these markers than trauma itself. For example, PTSD diagnosis seems to add to the effect of trauma on serum MDA levels and PON1 enzyme activity. Thus, serum MDA levels and PON1 enzyme activity may serve as biochemical markers of PTSD diagnosis.

A Meta-Analysis of Oxidative Stress Markers in Depression

OBJECT

Studies have suggested that depression was accompanied by oxidative stress dysregulation, including abnormal total antioxidant capacity (TAC), antioxidants, free radicals, oxidative damage and autoimmune response products. This meta-analysis aims to analyse the clinical data quantitatively by comparing the oxidative stress markers between depressed patients and healthy controls.

METHODS

A search was conducted to collect the studies that measured the oxidative stress markers in depressed patients. Studies were searched in Embase, Medline, PsychINFO, Science direct, CBMDisc, CNKI and VIP from 1990 to May 2015. Data were subjected to meta-analysis by using a random effects model for examining the effect sizes of the results. Bias assessments, heterogeneity assessments and sensitivity analyses were also conducted.

RESULTS

115 articles met the inclusion criteria. Lower TAC was noted in acute episodes (AEs) of depressed patients (p<0.05). Antioxidants, including serum paraoxonase, uric acid, albumin, high-density lipoprotein cholesterol and zinc levels were lower than controls (p<0.05); the serum uric acid, albumin and vitamin C levels were increased after antidepressant therapy (p<0.05). Oxidative damage products, including red blood cell (RBC) malondialdehyde (MDA), serum MDA and 8-F2-isoprostanes levels were higher than controls (p<0.05). After antidepressant medication, RBC and serum MDA levels were decreased (p<0.05). Moreover, serum peroxide in free radicals levels were higher than controls (p<0.05). There were no differences between the depressed patients and controls for other oxidative stress markers.

CONCLUSION

This meta-analysis supports the facts that the serum TAC, paraoxonase and antioxidant levels are lower, and the serum free radical and oxidative damage product levels are higher than controls in depressed patients. Meanwhile, the antioxidant levels are increased and the oxidative damage product levels are decreased after antidepressant medication. The pathophysiological relationships between oxidative stress and depression, and the potential benefits of antioxidant supplementation deserve further research.

Lowered paraoxonase 1 (PON1) activity is associated with increased cytokine levels in drug naïve first episode psychosis

BACKGROUND

Activated immune-inflammatory pathways play an important role in the pathophysiology of schizophrenia. Paraoxonase 1 (PON1) activity is inversely associated with inflammatory responses in numerous clinical conditions. The aims of this study were to delineate serum arylesterase PON1 activity in drug-naïve first episode psychosis (FEP) patients and a healthy control group, and to assess whether there are inverse relationships between PON1 activity and cytokine levels.

METHODS

A total of 51 drug-naïve FEP patients and 61 healthy controls were enrolled in this study. Levels of interleukin (IL)-4, IL-10, IL-6, tumor necrosis factor (TNF)-α and activity of PON1 were quantified.

RESULTS

Compared to healthy controls, FEP patients showed lower serum PON1 activity and higher levels of IL-4, IL-10 and TNF-α. A significant inverse relationship between PON1 activity and IL-4, IL-6 and IL-10 levels was detected, but not for TNF-α. Subjects with very low PON1 activity (25th quartile) presented significantly higher levels of IL-6, IL-10 and IL-4 than those with higher PON1 activity (75th quartile).

CONCLUSION

The present study provides evidence that FEP is characterized by an inverse relationship between lowered activity of the anti-inflammatory/antioxidant enzyme PON1 and increased cytokine levels, including IL-6, IL-4 and IL-10. It is hypothesized that lowered PON1 activity may play a role in the immune-inflammatory response that accompanies FEP and that increased cytokine levels may further modulate PON1 activity.

Markers of Oxidative Stress and Neuroprogression in Depression Disorder

Major depression is multifactorial disorder with high prevalence and alarming prognostic in the nearest 15 years. Several mechanisms of depression are known. Neurotransmitters imbalance and imbalance between neuroprogressive and neuroprotective factors are observed in major depression. Depression is accompanied by inflammatory responses of the organism and consequent elevation of proinflammatory cytokines and increased lipid peroxidation are described in literature. Neuropsychiatric disorders including major depression are also associated with telomerase shortening, oxidative changes in nucleotides, and polymorphisms in several genes connected to metabolism of reactive oxygen species. Mitochondrion dysfunction is directly associated with increasing levels of oxidative stress. Oxidative stress plays significant role in pathophysiology of major depression via actions of free radicals, nonradical molecules, and reactive oxygen and nitrogen species. Products of oxidative stress represent important parameters for measuring and predicting of depression status as well as for determining effectiveness of administrated antidepressants. Positive effect of micronutrients, vitamins, and antioxidants in depression treatment is also reviewed.